The Port Gamble S’Klallam and Nisqually tribes are studying herring spawning in Puget Sound, with hopes of eventually rejuvenating the population.
Herring are a crucial food source for other species, including juvenile and adult salmon. They are high in fat, which juvenile chinook salmon need when migrating to the ocean, said Hans Daubenberger, the Port Gamble S’Klallam Tribe’s senior research scientist. Juvenile salmon often feed on herring larvae in Port Gamble Bay during spawning season.
The Port Gamble S’Klallam Tribe supplemented herring habitat in the bay this spring by dropping tree branches into the water and experimenting with traditional methods of harvesting herring eggs, he said. Tribal members used to hang branches off floats or logs in Port Gamble Bay. Herring spawned on the branches, which were then pulled out by tribal members to harvest the eggs.
“It’s a really nutritious food source,” Daubenberger said. “It’s not just nutritious for wildlife, it’s a great food source for humans too.”
The tribe used hemlock boughs, some attached to buoys with rope, some attached to a floating PVC pipe, to create a surface area for herring to spawn. The tribe also observed kelp lines in the bay, which is another natural habitat where herring spawn.
Washington Department of Fish and Wildlife surveys of the winter spawning season in the bay reported very light spawning events this year, said Heather Gordon, an ecology consultant working with the tribe.
Historically Port Gamble Bay had one of the largest herring stocks in Puget Sound, but it started to rapidly decline in 2000, to the detriment of the region’s marine food web and ecosystem, Daubenberger said.
The idea for the project came from the salmon recovery organization Long Live The Kings and the Nisqually Tribe, who are working to restore herring populations in South Sound. Unfortunately, neither effort has succeeded so far in attracting herring to spawn in the tree branches.
That doesn’t mean the effort won’t be fruitful in the future, said Nisqually salmon recovery biologist Jed Moore. Herring populations can be fickle where they spawn, he said.
“Herring shift spawning locations. Their timing is reliable, but they make choices to maximize egg survival,” he said. “So there are a lot of factors interacting in ways we don’t yet under-stand. The herring can seem picky. Some years they spawn heavily in an area, other years they’ll ignore it completely. Sometimes they’ll shift, sometimes they’ll come back.”
The Nisqually Tribe launched two efforts last year to study herring: sinking trees to attract spawning, and rake surveys to search for eggs in beds of eelgrass or other materials known to be popular with herring. The work is meant to supplement the state’s larger-scale studies, Moore said.
“Can we find smaller spawning events in areas that have flown under the radar of the state’s studies, which are examining larger trends?” Moore said. “The Nisqually Tribe and Long Live the Kings, our research collaborators, are trying to find more localized trends.”
This year, the Nisqually Tribe is adding a third effort. They’ll catch herring with a technique called jigging, where lured hooks are lowered trailing off a lead weight. A grant from the nonprofit SeaDoc Society will fund genetic analysis of about 200 samples, to be conducted at the University of Washington.
The goal is to learn more about the herring’s spawning timing, which is driven by genetics, Moore said.
“I don’t think many people are aware of how important herring and other small fish are to the ecosystem of Puget Sound,” Daubenberger said. “At the end of the day, we’re trying to restore these species and this habitat, so that our tribal community continues to live as part of that natural environment.”
Ashley Bagley, project coordinator for Long Live the Kings, prepares to check cedar boughs for herring eggs in South Puget Sound in 2021. The boughs were sunk in places where Nisqually tribal members used to attract herring to spawn. Photo: Debbie Preston. Story: Trevor Pyle and Tiffany Royal.